The present disclosure relates to compositions, systems, and methods for treating subterranean formations, and more specifically, compositions, systems, and methods for the removal of sulfur-containing species encountered in subterranean formations.
Fluids in sewage systems, fluids produced from wells, and make-up fluids frequently contain hydrogen sulfide. Hydrogen sulfide gas is toxic with a density heavier than air, and therefore removal or inactivation of this sulfide ion is necessary to prevent poisoning of personnel and contamination of the area. Moreover, hydrogen sulfide gas is highly corrosive to pipelines and equipment used in the operation of an oil well. Sulfides may also react with other components in the system, causing undesirable reactions and products. Thus, removing hydrogen sulfide from produced fluid and gas is necessary for safe production.
In drilling some subterranean foiniations, and often particularly those bearing oil or gas, hydrogen sulfide accumulations are frequently encountered. Drilling fluid, used to convey cuttings to the surface, also brings hydrogen sulfide to the surface. Such sulfide in the drilling fluid is problematic because it can corrode the steel in the drilling apparatus and may be liberated into the atmosphere as toxic sulfide gas at the well surface. Scavengers are necessary to react with sulfides and form products that are nonhazardous and noncorrosive.
There are several classes of sulfide scavengers available, including nitrogen-, aldehyde-, and acrylate-based scavengers, but many have serious limitations. For example, triazine-based hydrogen sulfide scavengers have been commonly used in the industry, but triazine can increase the pH values of produced water and cause scale problems. Nitrogen-free scavengers such as formaldehyde, glyoxal, and acrolein create added difficulties for transportation, storage, and operation due to their toxicity and corrosivity. In contrast, non-aldehyde scavengers are less volatile, easier to handle, and easier to store, but they suffer from reduced reaction rates under neutral conditions.
While embodiments of this disclosure have been depicted, such embodiments do not imply a limitation on the disclosure, and no such limitation should be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.